人工湿地系统对污水磷的净化效果

建立以亚热带湿生、水生植物为主的十二套下流行一上流－上行流人工湿地系统作为处理城镇生活污水的对策。以其中四套研究其在不同的水力负荷及气候条件下对污水中磷的去除效果。人工湿地系统随处理运行时间的推移趋于稳定，对污水中的总磷、无机磷显示较好的净化效率，平均去除率在冬季达到４０％以上，夏季达到６０％以上，出水达到国家地面水Ⅲ级标准。水生植物在系统中起到明显作用，有植物系统的除磷效率及稳定性均高于无植物对照，其中２号茭白－石菖蒲系统的效果最好，总磷平均去除率为６５％。４号9蔗－苔草系统在高水力负荷下的净效果优于２号。水力负荷的增加对系统的净效果没有明显影响。

PRIMARY STUDIES ON THEPURIFICATION EFFICIENCY OF PHOSPHORUS BY MEANS OF CONSTRUCTED WETLAND SYSTEM

Twelve sets of macrophyte-planted upflow-downflow constructed wetland systems were set up to treat municipal wastewater.Four of these plots were selected to study their purification efficiency of phosphorus under different hydraulic loading rates.The plots turned to be more stable and showed better purify efficiency of total phosphorus (TP) and inorganic orthophosphate (IP) through the operation.The average removal rates of total phosphorus are more than 40% in winter and 60% in summer.The outflow meets the grade Ⅲ national criteria of surface water (GB 3838-88).The planted plots have better and more stable purify efficiency than the control plot. From average removal efficiency.plot 2 with Zizania latifolia and Acorus tartarinowii was the best one with an average removal rate of TP 65%. But under higher hydraulic loading,plot 4 with Scirpus triqueter and Carex sp. was better than plot 2. The increasing of hydraulic load did not markedly influenced the efficiency of the plots.